The invention relates to a mounting arrangement for an intake manifold and a method of making same. In particular, it is concerned with connecting an intake manifold to a cylinder head of an engine without the use of a mounting flange and flange bolts.
The design of plastic intake manifolds has been particularly challenging in view of acoustical and mounting requirements. For example, previously known intake manifolds have been designed taking into consideration the necessity of providing adequate accessibility for flange bolts as well as the need for flat seating surfaces for the flange bolts.
European Patent Application 0 567 702 A1 discloses a method for molding an intake manifold for a motor vehicle. Upon fabricating the intake manifold by a blow-molding procedure, a flange for promoting the introduction of crankcase gases is formed around the pipes of the intake manifold by an injection molding process.
UK Patent Application GB 2 203 487 A discloses a component for the introduction of crankcase gases which is arranged between a cylinder head and an intake manifold of an internal combustion engine. The component is formed with fuel injectors having associated fuel feed and return passages and air feed passages in communication with the engine cylinders.
International Patent Publication WO97/34081 discloses a relatively complicated system having a flange for distributing vapors or gases to the cylinders of an engine to insure balanced flow. An intake manifold mounting flange includes a face having a common network of flow passages formed by grooves for mixing crankcase and purge vapors. Another separate sealed network of grooves directs exhaust gas. Yet another network of grooves in the flange face directs a flow of assist air to injector ports.
U.S. Pat. No. 5,353,752 discloses an intake system for an internal combustion engine. The intake system includes four branch pipes which connect with an intake manifold having upstream and downstream portions. The downstream portion is arranged with four injectors for injecting fuel to each cylinder and is connected to the cylinder block via gaskets.
It is an object of the invention to more effectively isolate an intake manifold from vibrations caused by the operation of the engine.
This object is achieved by providing a mounting arrangement for an intake manifold which comprises an adapter plate attached to a cylinder head of an engine and providing the adapter plate with at least one aperture comprising a smooth inner surface. The intake manifold comprises at least one inlet pipe which is mounted to the adapter plate by arranging the at least one inlet pipe in the at least one aperture of the adapter plate. A securing mechanism is arranged between the at least one inlet pipe and the smooth inner surface of the at least one aperture for securing holding the inlet plate in place during operation of the engine.
According to the invention, the adapter plate allows the intake manifold to be vibrationally isolated from an engine by allowing the runners or pipes of the intake manifold to be secured within the apertures of the adapter plate.
The mounting arrangement of the present invention thereby eliminates the need for mounting flanges and flange bolts for mounting the intake manifold to the engine. In the past, these mounting flanges have caused engine vibrations to be transferred to the intake manifold. Furthermore, the elimination of the mounting flanges provides an intake manifold which can be relatively easily fabricated and readily mounted to a cylinder head.
According to further preferred embodiments of the present invention, the securing mechanism which is arranged between the runner or pipes of the intake manifold and the smooth surfaces of the apertures of the adapter plate can comprise an O-ring or a glued connection which operate to effectively isolate vibrations.
According to yet another further preferred embodiment of the present invention, a portion of the intake manifold is attached to a valve cover by way of grommets to further isolate the intake manifold from engine vibrations while operating to securely mount the intake manifold.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.